Changes in phenolic profile, soluble sugar, proline, and antioxidant enzyme activities of Polygonum equisetiforme in response to salinity

Authors : Fayçal BOUGHALLEB, Raoudha ABDELLAOUI, Maher MAHMOUDI, Esmaeil BAKHSHANDEH

Pages : 25-35

View : 12 | Download : 5

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :This study intended to focus on the effect of different levels of NaCl insert ignore into journalissuearticles values(0?400 mM, at regular intervals every 100 mM); on the growth, secondary metabolites, and antioxidant enzyme activities of Polygonum equisetiforme, a wild plant with medicinal and industrial uses, which often grows in harsh environmental conditions. Our results showed that biomass production significantly decreased with salinity, while the leaf relative water content declined only at high levels of NaCl concentration insert ignore into journalissuearticles values(300?400 mM);. In contrast, these higher doses of salt resulted in a significant increase in malondialdehyde insert ignore into journalissuearticles values(MDA); content. Both proline and soluble sugar insert ignore into journalissuearticles values(e.g., fructose, glucose, and sucrose); contents were enhanced under saline conditions. The methanolic extracts of the shoots included 10 flavonoids and 9 phenolic acids. The total phenolic acids insert ignore into journalissuearticles values(TPA);, total flavonoid compounds insert ignore into journalissuearticles values(TFC);, and total phenolic compounds insert ignore into journalissuearticles values(TPC); increased with salinity, particularly at 300 mM NaCl. An increase in TPA resulted especially from an increase in quinic, gallic, and protocatechuic acids insert ignore into journalissuearticles values(phenolic compounds);, followed by quercetin-3-O-galactoside, catechin, and epicatechin insert ignore into journalissuearticles values(flavonoid compounds);. Superoxide dismutase insert ignore into journalissuearticles values(SOD); activity increased only at high salinity levels insert ignore into journalissuearticles values(>200 mM);, while glutathione reductase insert ignore into journalissuearticles values(GR);, guaiacol peroxidase insert ignore into journalissuearticles values(GPX);, catalase insert ignore into journalissuearticles values(CAT);, and ascorbate peroxidase insert ignore into journalissuearticles values(APX); activity increased with salinity level. A positive significant correlation between antioxidant DPPH and TPA, TFC, TPC, CAT, and APX suggests a vital protective role in controlling oxidative stress through the scavenging process. Consequently, our results indicated that P. equisetiforme shoots are rich in secondary metabolites, especially phenolic compounds with high potential antioxidant activities. It can be considered a salt-tolerant species able to survive at salinity levels up to 300 mM NaCl.
Keywords : Polygonum equisetiforme, salt stress, osmolytes, secondary metabolites, antioxidant enzyme activities